Pressure regulating mechanism



Oct. 3, 1950 F. E. MILLER ETAL PRESSURE REGULTING MECHANISM Filed Nov. 26, 1948 INVENTRS %G.M

Patentec ct. 3,, 195

PRESSURE REGULATING MECHANISM Frank E. Miller, Edgewood, and Ralph T. Whitney, Irwin, Pa.

Application November 26, 1948, Serial No. 62,054

8 Claims.

This invention relates to pressure reguiating devices for maintaining a substantially constant pressure, or a pressure varying between chosen limits, on an element through relatively long travel of said clament.

In cigarette lighters of the type embodying a manually operated steel spark wheel having a serrated face engaging the end of a flint for producing a spark upon turning of the wheel against the flint, the flint must be pressed against the wheel with force. A relatively long spring is usually employed for thus urging the flint against the wheel and when the flint is new the pressure of the spring is so great that it is not only difiicuit to turn the wheel but the flint wears away abnormally rapid. On the other hand before the flint is completely Worn away it has to be discarded because, due to extension of the spring, the pressure of the flint against the wheel has become so reduced as to be insufiicent to produce a spark upon rotation of the wheel thereagainst. It has been found that only during some intermediate portion of the length of the flint is the pressure of the spring against the flint such as to permit turmng of the wheel with case and Without undue wear of the flint and yet positively insure sparking.

'Ihe principal object of the invention is therefore the provision of a mechanical pressure regulating means for delivering and maintaining a desired degree of force, either substantially constant, or within desired limits, from a force applying medium such as a spring, on an element throughout relatively long travel or wear life of said element.

In accordance with the object as applied for example to a cigarette lighter, the pressure regu lating means interposed between the pressure medium or flint actuating spring of the lighter, and the flint itse1f. The pressure medium is provided With adequate initial pressure or stored force to press the flint against the spark wheel throughout the wear life of the flint, and the pressure regulating means is operative tu automatically limit the amount of force applied from the pressure medium to the flint throughout its full wear life to a substantially constant, desired degree to facilitate easy turning of the spark wheel and yet assure production of sparks and maximum life of the flint. It has been found in practice that the force of the pressure medium may be many times that required to press the flint against the spark wheel to insure the production of an adequate spark, and that the pressure regulating means Wi1l consistent1y feed this force to the flint in just the right degree to obtain the desired results.

The pressure regulating means may take various forms as Will be hereinafter described, and the primary pressure medium need not be a spring asemployed in cigarette lighters as will later become obvious. Moreover the invention is not limited in use to cigarette lighters but may be employed wherever it is desired to maintain an element under substantially constant pressure, or under pressure within a chosen range of pressures, throughout relatively long movement of said element. As further examples, the pressure regulating means is especially adapted for regulating pressure of brushes against armatures in electric motors and for maintaining a chosen pressure on a body of liquid, such as in a lubricant system.

Other objects and advantages Will become apparent from the following more detailecl description of the invention.

In the accompanying drawing; Fig. 1 is a crosssectional view of a portion of a cigarette lighter embodying one form of the invention; Figs. 2, 3, 4 and 6 disclose other embodiments of the invention; and Fig. 5 is a bottom plan view of the embodiment shown in Fig. 4.

Description As shown in the drawing, l designates the usual housing of a cigarette lighter employed for illustrating one use only of the invention, 2 the manually operative steel spark wheel, 3 the flint, the end of which engages the serrated peripherial face of said wheel, and 4 a source of power such as the usu-al spring for pressing said flint against said wheel with force to produce spark upon turning said wheel against said flint. The flint 3 is slidably mounted in a suitable bore 5 in the casing i along with the spring 4, a cap 6 being secured to said casing for maintaining said spring compressed against the flint 3. The spring 4 differs from th0se ordinarily employed only in that it isdesigned to provide at least adequate force of the flint 3 against wheel 2 to ensure the production of sparks when the flint is substantially completely worn away, but at this time the force of spring 4 may be much greater, if desired, since the pressure regulating means, to be presentiy described, regulates the amount of force transmitted from said spring to said flint and thereby limits the pressure of said flint against wheel 2 to just the correct amount.

According to the invention as disclosed in Fig. 1, the pressure regulating means may comprise a cylindrical resiiient element 1 preierably made of material such as rubber, movably disposed in bore 5 and located between and engaging With the adjacent ends of the flint 3 and spring 4. After the lines et contact with the wall cf bore than the connection with flint Hencc a certain reactive force from flint 3 is capable of overcoming a rnuch greater force of spring 4 to cause the circular edges of segments Mi to be forced into lock ing engagement with the wall of bore 5 by said spring and thereby limit the amount of force applied to flint 3.

The structures shown in Figs. 3, 4 and 5 of the dravving W111 limit transmission of force from spring 5 to flint 3 to a substantiaily constant degree but in each case the arnount of force transrnitted may be predetermined, as in Fig. 3, by the location of the connection betvveen the dise H and flint 3 and spring 4, and in Fig. 4. by proper selection of the line of contact between spring 4 and the segments l l to provide the desired ratio of lever arme for the force of spring 4 reactance from flint 3.

If for some certain use of the invention dis closed in Figs. 3 and 4 of the drawing, it is desired to provide a definite range of pressure change on the flint 3 this may be accomplished by interposing a spring l6 between the flint 3 and the pressure regulating means, such as il, as shown in Fig. 6 of the drawing. In accordance with this modification, the pressure regalating means li Will inch up upon a chosen reduction in reactance from spring li; until such reactance is increased to the necessary degree to stop such movement, whereupon the pressure regulating means H wi11 remain stationary until the reactance of spring 1165 again reduces, due for example to wear cf flint 3, to a degree to release the pressure regulating means il from the wall of bore 5 to a degree sufiicient to per mit spring 1 to again effect movernent thereof.

It will novv be seen that we have provided a mechanica] pressure regulating means which is automaticaliy operative in accordance with opposing forces et a power source and the reactanse of a pressure operated element to maintain a pressure on said element substantially constant, or Within predetermined limits, for a relatively long movement Of said element. The pressure regulating means permits initial stor mg of sufiicient energy in the power source t0 insure at least the desired or substantially same pressure on the pressure operated element at the end of its traverse as provided thereon at the beginning of its traverse.

Having now described the invention what we c1aim as new and desire to secure by Letters Pat ent is:

1. Mechamsm for mantaining a substantialiy uniform degree of advancing pressure onrnovable, force opposed, means, said mecnanism ccm prising in combination with said means, power means for moving said force opposed means, a part fixed With respect to said force opgosed means, and resilient means operative Z03 reactive force of said force opposed means to render said power means effective to expand said resilient means into gripping relation With said fixed part for thereby limiting pressure applied to said force opposed means by said power means to a fraction of that of said power means.

2. A structure as defined in claim 1 in Which the resilient means comprises a rubber-like clement subject opposingly to reactive force of said material and pressure of said power means and which when free has substantiel sliding contact with said fixed part.

3. Means for maintaining a substantially uniform degree of advancing pressure on a movab1e, force opposed eiement slidable in a bore, said means comprising in ccmbinatiom With said element and the wall of said bore, power means for moving said element, and resilient means in said bore subject to pressure of said power means and reactive force of said element and expansible b a chosen degree of said reactive force into gripping relation with the wall of said bore for thereby limiting pressure applied to said clement by said povver means to a fraction of that of said power means. r

4. A structure as defined in claim 3 wherein said resilient means comprises a flexible metal dished disk disposed With its peripheral edge in sliding contact With the wall or the bore and subject on its concave face t0 pressure of said povver means and on its oonvex face tu reactive force of said element applied doser to the center of said disk than the pressure cf said power means. V

5. A structure as defined in claim 3 wherein said resilient means comprises a pluraltty of levers radiating from the axis of said bore in spaced apart relation and providing a generally concave structure with the adjacent ends of said levers at the convex side of said concave structure operatively connected to said slidable clement and the opposite ends in contact With the wall of said bore and subject on the concave side of said structure, adjacent said opposite ends, to pressure of said poWer means.

6. A structure as defined in claim 3 comprising means securing said resilient means to said povver means.

7. Means for maintaining a substantially uni: form degree of advancing pressure on a rr1ovable, force opposer] element, said means comprising in combination With said element, a spring acting on said element for applying advancing pressure thereto, power means for compressing said spring, a fixed element, and resilient means connecting said spring and povver means operative 1 by reactive force of said spring into gripping relation with said fixed element to limit pressure applied to said spring by said power means to a fraction only of the pcwer of said power means.

8. A mechanism for advancing in a casing bore, or the 1ilre, and for limiting the pressureof a member against a movable clament, such as the pressure of a flint against the spark wheel of a cigarette lighter, said mechanism comprising in combination with said member and wall of said bore, a spring confined in said bore under a pressure to provide at least the desired advanoing pressure on said element through out its full traverse, and resilient means disposed in said bore between said clament and spring operative by reaction of said desired pressure on said clement into gripping engagement With said Wall for limitine the pressure applied by said spring t'o said member to said desired pressure.

The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Mossinghof Apr. 3, 1945 Number 

